export var max = function (n1, n2) {
  return Math.max(n1, n2);
};
export var len = function (arr) {
  arr = arr || [];
  return arr.length;
};
export var indexOf = function (str, key) {
  console.log('str.toLocaleLowerCase()', str.toLocaleLowerCase().indexOf(key));
  return str.toLocaleLowerCase().indexOf(key);
};